Control valve device



June 20, 1950 R. E. WATSON CONTROL VALVE DEVICE Filed May 22, 1947 2Sheets-Sheet 1 INVENTOR. Robert E. Watson QFMAQM M ATTORMEY R. E. WATSONCONTROL VALVE DEVICE June 20, 1950 2 Sheets-Sheet 2 Filed May 22. 19470% mm mm m EW INVENTOR ROB ERT EWATSO N ,4) .-ITTORNEY Patented June 20,1950 UN 1 STATES PATENT OF Fl CE 2,512,046 CONTRUL VALVE DEVICEFRobent-E. Watson, Edgewood, Pa., assignor to The Westinghouse AirBrakeCompany, Wilmerding, Pa a corporation of Pennsylvania-ApplibatlfinMflYfZZ, 1947, Serial No. 749,677

This invention relates to control valve devices and more .particularlytoa control valve device for use in fluid pressure brake equipment of thetype disclosed in the patent to E. E. Hewitt et al., No. 2,173,940,issued September 26, 1939.

While locomotives "equipped with brake equipment of thetype disclosed inthe aforementioned patent meets entirely the present day brakingrequirements of the various railroads when run as a live engine, it hasbeen found that-when a locomotive so equipped is hauled as adead enginein a train, the control of the brakes on the dead engine may beadversely afiected by reason of an independent application and releasepistonnot moving completely into its application position.

One object of the invention is therefore to provide, in a brakeequipment of the type disclosed in the aforementioned patent, improvedmeans for positively eliminating the above mentioned undesirablefeature.

Another object of the invention is to provide a multipistoncontrolled'valve-device in which slight misalignments of the pistonboreswill not adversely affect or interfere with the operation of thevalve device.

Other objects and advantages will appear in the following more detaileddescription of the invention.

, In the accompanying drawings:

Fig. 1 is a diagrammatic view, partly in section and parth in-o'utline,of a locomotivebrake equipment embodying the invention; 'and,

.Fig. 2 is an enlarged sectional viewof an interlock portion of thecontrol valve device shown in l.

As shown in Fig. l of the drawings, the loco-- motive brake equipmentcomprises a combined automatic and straight air brake valve device 1,

- an independent brake valve device 2, a master switch 3, an applicationand releasemagnet valve device 4, a control valve device 5, a relayvalvedevice 6, a double heading cock I, and in addition, the usual apparatusto be rendered efiective when hauling a dead engine, which apparatuscomprises a cut-out cock '8 and azcombined air strainor and check valvedevice 9.

The equipment further comprises a brake pipe iii,- a straight air pipe iI, application and release Wires i 2 and I3, respectively, these pipesand wires extendin through the locomotive from one end to the other endbeing provided at their opposite ends with suitable couplings orconnectors (not shown) for connecting same to like pipes and vwires onother vehicles of thetrain.

The brake equipment further comprises amain '8 claims. (01. 202- 26.)

reservoir l4 adapted to be supplied with fluid under pressure in theusual manner, a feed valve device! 5 operates to supply fluid underpressure from said reservoir to a feed valve pipe Hi at the reducedpressure desired to becarried in the brake pipe 10, and a brake cylinder11 responsive to the pressure of fluid suppliedthereto to apply thebrakes on the locomotive.

:It will be understood that the equipment shown in Fig. l issubstantially the same as the equipment shown and described in theaforementioned patent, and that with the exception of an interlockportion l8 of the control valve device 5 shown in section in Fig. 2 andhereinafter described in detail, the par-ts of the equipment shown inFig. 1 may be identical in construction and operate in a similar mannerto corresponding parts of the equipment disclosed in the aforementionedpatent. However, in the present application only those parts of theequipment are shown and described which are deemed necessary to have aclearunderstanding of the invention.

Brieflyv described, the combined automatic and straight air brake valvedevice I comprises means 'by which the engineman maycontrol the brakeson the locomotive and cars of a train either by straight air by way ofthe straight air pipe H or automatically through the medium of fluidunder pressure in the brake pipe ID, a selector Ill'be'ing provided forthe engineman to select either-the straight air or the automatic controlof locomotive and train brakes.

'The independent brake valve device 2 is provided for controlling thebrakes on the locomotive independently of the brakes on the cars of thetrain and. is similar to that disclosed in Patent No. 2,173,940, issuedSeptember 26, 1939. This brake'va'lve device is provided .with means forcontrolling the operation of a self-lapping application and releasevalve mechanism, a cut-ofi valve, an application delay valve, and alookout valve mechanism "20. Since a detailed description of the lockoutvalve mechanism 20 only is deemed essential to a clear understanding ofthe invention, a detailed showing and description of the other abovementioned parts of the independentjb rakevalve device 2 have beenomitted.

The lockout valve mechanism 29 comprises a plunger 21 slidab'ly mountedin a suitable bore in the brake valve casing and carried by a spring .22supported on a valve '23. The valve 23 is contained in a chamber 24which is always open to atmosphere by way of a vent port 254 The valve23 is slidably mounted ina suitable bore; in the'casing by meansof afluted stern which extends through said bore into a chamber where itengages a fluted stem of an oppositely disposed valve 2?. The chamber 26is connected by way of a passage 28 to a pipe 29 leading to theinterlock portion l8 of the control valve device 5. The valve 27 iscontained in a chamber 33 which is", connected to the niainreservoirvlfi by way of a passage 3!; a branch pipe 32 and a mainreservoir pipe 33. A spring 34 is disposed in the chamber 30. so as toact on the valve '27- in a direction for seating said valve and ior unseating the valve 23, the spring 3d being of sufiicient strength to beable to act-through the mic-* dium of said valves and the spring22 tohold'the plunger ii in its normal position in which it is" shown in thedrawing.

I! in accordance with variations in the pilot or control pressure inpipe 44, in the usual manner.

The control valve device 5 comprises a service valve portion 41, anemergency valve portion 48, the interlock portion 18, a pipe bracket 49and a filling piece 50. This control valve device 5, ex-

.cept, for the interlock portion as previously mentioned, is"- the sameas or similar in function and construction to the control valve devicedisclosed in the aforementioned patent. Since a detailed pdescription ofthe intricate construction and operation of the service and emergencyportions of wthe control valve device 5 is not essential to a a bail 35pivotally mounted in the casing, "by

means not shown, for engagement by handle 36 and for downward movementthereby against the upper end of the plunger 2|. Continued downwardmovement of the handle 35, acting through the medium of the bail 35,plunger 21 and spring 22, is adapted to effect seating of the valve 23 Jand unseating of the valve 21 against the pressure of the'spring- 34.The release of manual pressure on the handle 36 permits operationof-spring: 34 to seat va1ve2'l and unseat valve 23, all of which isdescribed in the aforeinentionedpatent;

The master switch 3 is provided for controlling the'energization anddeenergization of the application and release wires l2 andlt whenstraight air control of the brakes is used. This switch} comprises adiaphragm assemblage (not shown) subject to the opposing pressures offluid in the straight air pipe I l and fluid in a control pipe 3! whichmay be connected at one time to a'service control pipe 38 and at anothertime to an emergency control pipe 39. i i Y The application and releasemagnet jvalve device comprises an application. magnet 43*and 'a releasemagnet 4!. One terminal oi'the magnet 48 is connected to the applicationwire I Z'andone terminal of the magnet M is connected to the rei leasewire l3 while 'the other terminal magnet is connected to ground.

The release magnet 4| operates uponene'rgization to seat a release valve(not shown) for "clos- .dfsac ing an atmospheric communication: tojthestraight air pipe I I. Deenergizat'ion ofthe magnet 4| permits a spring(not shown) to unseat the release valve. v

The application magnet 40 upon energization shown) so as to supplyfluidunder pressure; from an auxiliary reservoir 42 to the straight airpipe II by way of a pipe 43. Deenergization of the magnet 40 permits aspring (not shown) to seat operates to unseat an applicati 1---;

the application valve, for closing communication between the auxiliaryreservoir 42 and the straight air pipe ll. j "l The relay valve device 6is of the type adapted to operate in response to pressure of fluid suD-plied thereto by way of a pipe 46, which is in open communication with abrake application and release passage 55 in the brake controlvalvedevice 5, to supply fluid under pressure delivered by way of pipe33 from the main reservoir [4 to the brake cylinder I"! by way of a pipe46 for applying the brakes on the locomotive. The relay valve device 5is operative in response toa reductionin the pressure of fluid in thepipe 44 to reduce the'p're'ssure of fluid in the brake cylinder Hto asimilar h degree. erative to vary the pressure in the brake cylinder Inother words, the valve 'devicefi is on- I jzclear, understanding of theinvention it is not 15' deemed necessary to show and describe these v w1 partsin detail Resting on the upper end of the plunger 2| is saidcheck valve, or a passage 56 open to the opposite end of the checkvalve. In the position in which the check valve 5! is shown in Fig. 2

:the passage 45' is disconnected from the passage 56 and connected topassage 55. Upon movement of the checkvalve 5| to its upper position,

passage 45 will be disconnected from passage 55 and connected topassage56.

The double check valve 52 is like the double check valve 5! andis'provided to control communication between passage 55 and either astraight air passage 51 at one end of the device or an independentapplication and release control-passage 58 at the'opposite end of thedevice.

Theindependent release valve 54 is provided for '-the purpose ofcontrolling communication between-passage 45 and a local atmosphericpassage 59 and is provided on one side with a gasket 59a 'for engagementwith a seat rib 60 and the closing 5 thereby of the atmospheric passage59. At the opposite side is a chamber 6| connected to a passage 62 andcontaining a spring 63 for urging the valve 54-to its seated position asshown in Fig. 2. Passage 62 leads to the selector valve device 53 andhas a check valve 64 disposed in said passage to" prevent back flow offluid under pressure in the direction away from said selector valvedevice to the chamber 6 l. A restricted port 65exte'nds through theindependent release valve -54 so'asto connect chamber 6| with passage 45to permit equalization of the fluid pressures act- 'ing on the oppositesides of said valve so that the spring63 will be enabled to hold thevalve 54 in the position for closing communication between passage 45and the vent port 59.

The parts of I the interlock portion I8 so "far described re identicalwith the corresponding parts of the interlock portion shown anddescribed in the aforementioned patent. Howeverg in accordance with theinvention the interlock portion 8 has'been provided with the new andimproved selectorvalve device 53.

jThis improved selector valve device 53 comprises a casing havingtherein a bore 66 which is in constant open communication with the mainreservoir l4 by way of a passage 61, a

branch pipe 68 and the main reservoir pipe 33. slide valve 69 having anapplication position, in which it is shown in Fig. 2, and a releaseposition, into and out of which it may be actuated, is .mountedinthefbore 66 for operation in a manner to be hereinafter described.Secured by any suitable means to the casing over the lower end of thebore 66 is acap portion"!!! with the interior thereof adjacent to thebore 66. This cap portion 70 contains a piston assemblage H foroperating the slide'valve (i9,

which assemblage also serves to close off the lower end of the bore 66from the interior of the cap portion The piston assemblage 1| enclosedin the cap portion ll! comprises a sleeve member 12 clamped at itsperiphery between the cap portion is and a portion of the casing. Agasket '13 is provided to effect a seal between the sleeve member H andthe casing, and thus prevent-s leakage of fluid under pressure aroundsaid sleeve member between bore 6'6 and the interior of cap portion 10.Thesleeve member 12 has a through axial bore 14 in which a piston i5 isslidably mounted, the piston having'at its inner or upper face a chamber16 which is always connected to bore 68 and passage 61 and at its loweror outer face a chamber H which is constantly open to atmosphere by wayof a port it. The piston is provided with a positively connected notchedstem 19 connected to slide valve 89 by means of which said slide valvemay be actuated as hereinafter described.

The piston assemblage 11 further comprises a piston member 80 of largerarea than piston l5 and slidably mounted in a bore 8| in the cap portionit. 'lh-episton member 80 has the chamber H at one face and at the otherface a chamber 82, which latter chamber is in constant opencommunication by way of a passage 83 with the pipe 25; leading to thepassage 28 in the independent brake valve device 2.

The piston member 89 is provided at its outer side with a guide portion84 which is slidably carried in a reduced portion of the bore M. In theinner face of the piston member 89 is a recess 85 having at the mouththereof a series of radially inwardly extending projections 86 forsliding engagement with the outer periphery of the sleeve portion 8'! ofthe sleeve member 72. At the bottom of the recess 85 is a boss 88 bymeans of which the piston 80 may engage and actuate the piston l5 withinthe sleeve 12.

6, Von M by way of the passage 61, branch pipe 68 and pipe 133; 'Thus,when the independent brake "valve handl'36is in" its raised positionfluid at main reservoir pressure acting on the inner face of the pistonliprepbndrats and holds piston 15 in its lowermostor normal position inwhich his shownin'Fi'g. "2.

Now when it is desired to effect an independent release'of the brakes,as 'describediin the aforementioned patent, 'the'handl'e 36 of theindependent brake valve device "2 is depressed; by which 'movementi'thevalve '23 is seated and the lookout valve 21 is. unse'ated. Opening ofthe lookout valve *2? permits'fluid under pressdre to flow from the mainreservoir in to the chamber 82 at the outer face of the piston member813 by way of the passage '28, pipe YES-and passage 83 in the interlockportion'ifi; In response to this fluid at mainreservoir pressurethepiston iember 883. is moved upward into engagement with the 'piston lli.Withthe opposing pressures acting on" piston 75 and piston member 8'!)being jthesame, and; since aspreviously described, the area of thepiston member 89 is greater than that ofpistonli, the force of saidpiston member prevails to move the piston I5 in an upward direction. Asthe pistonmember '8 0' thus moves it'acts throughthe' medium of its boss88, piston 75 and .stem 119t0 "cause slide valve 69 to move upwardlytoits independentrelease position, in which position an independent reell)It will thus be seen that, by reason of the guide portion 3 of thepiston member 80 engaging the wall of the bore in cap portion l'fl atone end of said piston member and the projections 86 of the pistonmember engaging the periphery of the sleeve 8? of the sleeve member'l2,the

piston member 33 is held in operative relation with the piston '55independently of their relative alignment;

It will here be understood that the operation of the piston 15 and theassociated slide valve 88 is controlled by the lookout valve mechanism26 in the independent brake valve device 2. For example, when theindependent brake valve handle 36 is in its normal raised position asshown in Fig. 1, the chamber 82 at the outer face of the piston member80 is connected to atmosphere by way of passage '83 in the interlockportion 58, pipe 29, passage 28 in the independent brake valve device 2,chamber 26, past the unseatedvalve 23 to chamber 24 and the port 25. Itwill be remembered that chamber TI is constantly open to atmosphere byway of port '18 and that the fluid in chamber 76 is always maintained atthe'pressure in the main reserlease of the brakes is effected in thesame manner as that'd'escribed in the-aforesaid patent.

It should be mentioned at this point that, although the patent referredto herein discloses the use of fiuid under pressure from the feed valvepipe, in' the chamber corresponding to chamber T6 in'this application,to effect the operation of a selector valve'device, this applicationshows and describes the operation of the 's'ele-ctorvalve device 53 'asbeing effected by fluid under pres sure from the main reservoir 14. Thishas been done for the sake of accuracy because the use of main'reservoirpressure as above described is now the ,general practice in railroadoperation. It shouldbeunderstood, however;'that this change does notaffect in any way the operation of the invention,'nor a completeunderstanding of the same.

I When the locomotive is run as a live engine, the handle o'f'thecut-out cock 8 is positioned so that communication between the brakepipe" Ill and the main reservoir pipe 33 is cut off and the equipmentoperates in identically the same mannor as fully described in theaforementionedpatent to control the brakes on the locomotive and thecars of the train.

If further information as to the function of the equipment when thelocomotive is run asa live engine is desired, reference maybe had to theprior, hereinbefore mentioned patent to E. E. Hewitt et al. v

' 'When a locomotive provided with this equipment is hauled dead in atrain, it is desirable to condition the brakevalve' device I and masterswitch v3 so that neither can be operated unintentionally or otherwise"interfere; with the usual service control of the brakes on the train bythe locomotive in control: In order" to accomplish this the valve I0! ofthedouble'hea'ding cock 1 is turnedfromthe position in 'which it isshown in Fig; 1 of the drawings to a position in which both the brakepipe IO'and' the'service'control pipe38 are cut ofi from the brake valvedevice I so that thebrake valve device'l on the dead 7 engine has nocontrol over a service application of the brakes efiected through thebrake pipe It or the straight air pipe ll, nor over a subsequent releaseof such an application.

It will be understood that on the dead locomotive the handle of thebrake valve device I will be maintained or carried in its runningposition and that the handle of the independent brake valve device 2will be carried or maintained in its normally raised position. With theindependent brake valve handle in its normal raised position as shown inFig. 1, the lookout valves 23 and 24 therein will be positioned as shownin this figure and chamber 82 in the selector valve device 53 of thecontrol valve device 5 will be vented by way of passage 83, pipe 29,passage 28 in the independent brake valve device 2, chamber 26, pastunseated valve 23, chamber 24 and passage 25.

When the locomotive is being hauled dead in the train, the compressor onthe dead locomotive will of course be inoperative and the compressed airfor operating the brakes on the locomotive must then be supplied throughthe brake pipe from the locomotive in control of the train. In order tocharge the main reservoir on the dead locomotive, the cut-out cock 8 onsuch locomotive is turned from its normal position, in whichcommunication between the brake pipe l and the main reservoir pipe 33 isclosed, to a position in which communication between said pipes isestablished. With communication between these pipes thus established,fluid under pressure flows from brake pipe Illv to the maini'rese'rvoirpipe 33 and thereby to the main reservoir 14, through cut-out cock 8 andpast the check valve and through a restricted port (not shown) in thecombined strainer and check valve device 9.

Fuild at brake pipe pressure thus'supplied to the main reservoir pipe 33flows therefrom by way of the branch pipe 68 and the passage 61, whichpassage extends through the pipe bracket 49 and filling piece 50, tobore 66 and chamber 16 in the selector valve device -18. With thechamber 'Il open to atmosphere by way of the port 18, and with chamber82 open to atmosphere by way of passage 83, pipe 23, passage 28 in thebrake valve device 2, past the normally unseated valve 23 to chamber 24and thenceby way of vent port 25, there is nothing to oppose downwardmovement of the piston'l'5 to its brake application position (if notalready there) except its own friction and that of the slide valve'69and the piston member 80. Consequently a slight increase in the pressureof fluid in chamber 16 will be suflicient to hold the piston 15 and theslide valve 89 in brake application position if they are already there,'or if not, only an increase in 'pressure suflicient to overcome theabove noted friction will be nec-. essary tov actuate the piston 15 andslide valve 69 to brake application position. 1

From the foregoing description, it will be noted that the chamber 1.! isalways open to atmos-. phere by way of port. 18 and that it is cut offfrom the-chamber 16 by the piston I and from chamber 82 by piston memberan. It should be understood that the port 18 is of such size that anyleakage of fluid under pressure. pastpiston or piston member 80, orboth, to chamber 11 will not cause a development of fluid pressuretherein substantially above that oi' atmosphere. Consequently, theproperoperation ofv the interlock portion l8 in response to the supply offluid under pressure to and release of fluid under pres; sure from thechamber 82 ispositively assured.

It will'also be noted that piston 15 and piston member are disposed inan improved and novel arrangement of such nature that they are notpositively connected together, so that slight misalignment of the onewith respect to the other will not adversely afiect their operation, andyet the necessary relative areas are provided in the structure forproperly positioning the slide valve 84.

In contrast to the present structure, the actuating piston in thecorresponding selector valve device disclosed in the aforementionedpatent is normally held, by reason of the pressure of fluid in the slidevalve chamber acting on the pistonexceeding the opposing pressure of aspring, in a position for permitting straight air application of thebrakes. When the brake equipment of a locomotive is not charged withfluid under pressure, such as when it is not in a train, the springholds the actuating piston and the slide valve in a position for anindependent release of the brakes.

When a locomotive with this prior selector valve device is placed in atrain to be hauled dead, the slide valve chamber of the device will becharged from the brake pipe through the usual cut-out cock, check valveand choke. By reason of the fact that the slide valve chamber is nowbeing supplied with fluid under pressure from the brake pipe instead offrom the main reservoir, the normal pressure of which on a livelocomotive is much higher than that of brake pipe, and by reason of theaforesaid choke and of a spring acting on the check valve in a directionfor seating it, the slide valve chamber is charged at a restricted rateand to a lower pressure than what is normally carried when thelocomotive is live. Under these conditions, if leakage past the selectorpiston is sufficient with respect to the rate of increase in thepressure of fluid in the valve chamber, insuflicient pressure will bedeveloped in the slide valve chamber to compress the spring an amountsuiiicient to actuate the piston over its full travel. Consequently, theslide valve will not be moved to a position to provide the proper portregistration for permitting a normal straight air brake application tobe effected by the leading locomotive.

In this improved selector valve device 53 there is no spring opposingdownward movement of the piston 15 and the associated slide valve 69, sothat only an increase in fluid pressure sufficient to overcome thefriction of the piston and slide valve is required. Since kineticfriction is lower than static friction, their downward movement oncestarted will continue until the slide valve is in straight air brakeapplication position, in which it is shown in the drawing.

It will thus be seen that, by reason of the novel arrangement ofopposing pistons having different effective areas and with a chamberbetween them open to atmosphere, there has been provided an improved andcompact means for positively moving the selector valve slide valve tothe straight air brake application position upon the locomotiveequipment being charged with fluid under pressure from the brake pipe l0while being hauled dead.

Having now described my invention, what I claim as new and desire tosecure by Letters Patent is:

1. In a fluid pressure brake, in combination, a valve having a brakeapplication position and a brake release position, a source of supply offluid under pressure, a first chamber constantly conest-eta pply, secondchamber at one time. supplied with fluid under pressure from said sourceof supply and. at another time vented to atmosphere,.atuhularmemberdisposed in said second chamber havingone end open to saidfirst chamber and. the other end open to said second chamber, a firstpiston slidably mounted in said member and connected to said valve, asecond piston slidably mounted upon said tubular member between saidsecond chamber and said third chamber for engaging andactuatin'g saidfirst piston, said second piston being operative in response to thepressure of fluid in said third chamber to engage saidfirst piston andthrough the medium thereof to actuate said valve to said brake releaseposition, and said first piston and said valve being operative to saidbrake application position by pressure of fluid in said first chamberupon venting of fluid from said third chamber.

2. In a fluid pressure brake, in combination, a source of supply offluid under pressure, a first chamber in constant open communicationwith said source of supply, a valve disposed in said first chamberhaving a brake application position and a brake release position, asecond chamber constantly open to atmosphere, a first piston foractuating said valve subject at one side to the pressure of fluid insaid first chamber and at the other side to the atmospheric pressure insaid second chamber, a guide member slidably supporting and encirclingsaid first piston, a third chamber at one time supplied with fluid underpressure and at another time vented to atmosphere, and a second pistonof greater area than said first piston and subject on one side to theatmospheric pressure in said second chamber and on the other side to thepressure of fluid in said third chamber, said second piston encirclingsaid guide member and being operative in response to an increase in thepressure of fluid in said third chamber to engage said first piston andthrough the medium thereof to actuate said valve to said brake releaseposition, and said first piston and said valve being operative to saidbrake application position by pressure of fluid in said first chamberupon venting of fluid from said third chamber.

3. A fluid pressure control valve device comprising a casing having anopen-ended bore, a cup-shaped element secured to said casing over theopen end of said bore and having internally a piston bore, a memberdisposed in said openended bore clamped between said casing and saidelement, said member comprising a sleeve of smaller diameter than saidpiston bore open at opposite ends and extending into said piston bore, apiston slidably mounted in said sleeve, a piston slidably mounted insaid piston bore and comprising means for contacting and moving thefirst named piston, said pistons serving to define a chamber betweentheir adjacent faces, means opening said chamber to atmosphere, meansfor conveying fluid under pressure to act on the opposite face of thefirst named piston, and means for supplying fluid under pressure to andreleasing fluid under pressure from the opposite face of the secondmentioned piston.

4. A fluid pressure control valve device comprising a casing having asleeve with an openended bore terminating therein, a cup-shaped membersecured to said casing over the open end of said bore and havinginternally a piston bore of larger diameter than said sleeve, a pistonin casing slidably mounted in said sleeve, a

movable member operatively mounted in said casing for movement by saidpiston, a piston slidably mounted in said piston bore. andccmprisingmeans for contacting and moving the first named: piston and thereby saidmovable member, said pistons servingto define a chamber between theiradjacent faces, means opening said chamber'lat atmosphere, means forconveying fluid under pressure to act on the opposite face of thefirst'named piston, and means for supplying fluid underpressure toand'releasing fluid under pressure from the opposite face of the secondmentioned piston. v

Q5. A fluid pressure control valve device comprising casing means havinga sleeve vvith an open-ended bore terminating therein, a cupshapedmember secured to said casing over the open end of said bore and havinginternally a piston bore of larger diameter, a movable memberoperatively mounted in said casing, a piston in said casing slidablymounted in said sleeve for actuating said movable member, a pistonslidably mounted in said piston bore and comprising means for contactingand moving the first men ticned piston and thereby said movable member,said pistons serving to define a chamber between their adjacent faces,means opening said chamber to atmosphere, means for conveying fluidunder pressure to the opposite face of the first named piston, and meansfor supplying fluid under pressure to and releasing fluid under pressurefrom the opposite face of the second mentioned piston.

6. A fluid pressure control valve device comprising casing means havinga sleeve with an open-ended bore terminating therein, a cupshaped membersecured to said casing over the open end of said bore and having aninternal piston bore of larger diameter than that of said sleeve, amovable member operatively mounted in said casing, a piston in saidcasing slidably mounted in said sleeve for actuating said movablemember, a piston slidably mounted in said piston bore and comprisingmeans for contacting and moving the first mentioned piston and therebysaid movable member, the second named piston being provided with a guideportion for reciprocal movement in a portion of said piston bore, bothof said pistons serving to define a chamber between their adjacentfaces, means constantly connecting said chamber to atmosphere, means forconveying fluid under pressure to the opposite face of the first namedpiston, and means for supplying fluid under pressure to and releasingfluid under pressure from the opposite face of the second named piston.

7. A fluid pressure control valve device comprising casing means havinga sleeve with an open-ended bore terminating therein, a cupshaped membersecured to said casing over the open end of said bore and havinginternally a piston bore of larger diameter, a movable memberoperatively mounted in said casing, a piston in said casing slidablymounted in said sleeve for actuating said movable member, a pistonslidably mounted in said piston bore and comprising means for contactingand moving the first mentioned piston and thereby said movable member,said pistons serving to define a chamber between their adjacent faces,means opening said chamber to atmosphere, means for supplying fluid at acertain degree of pressure to the opposite face of the first mentionedpiston, and means for supplying fluid at said certain degree 11 ofpressure to and for releasing fluid under pressure from the oppositeface of the second mentioned piston.

8. A fluid pressure control valve device comprising a casing having anopen-ended bore, a cup-shaped element secured to said casing over theopen end of said bore and having internally a piston bore in coaxialrelation to said openended bore, a member disposed in said openendedbore clamped between said casing and said element, said membercomprising a sleeve of smaller diameter than said piston bore open atopposite ends and extending into said piston bore, a piston slidablymounted in said sleeve, a piston slidably mounted in said piston boreand com prising means for contacting and moving the first named piston.said pistons serving to define a chamber between their adjacent faces,means opening said chamber to atmosphere, means for conveying fluidunder pressure to act on the opposite face of the first named piston,and means for supplying fluid under pressure to and releasing fluidunder pressure from the opposite face of the second mentioned piston.

' ROBERT E. WATSON.

REFERENCES CITED UNITED STATES PATENTS Name Date Neveu et a1 June 26,1934 Number

